/
SDL_syssem.c
180 lines (139 loc) · 3.3 KB
/
SDL_syssem.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
BERO
bero@geocities.co.jp
based on generic/SDL_syssem.c
Sam Lantinga
slouken@libsdl.org
*/
#ifdef SAVE_RCSID
static char rcsid =
"@(#) $Id$";
#endif
/* An implementation of semaphores using mutexes and condition variables */
#include <stdlib.h>
#include "SDL_error.h"
#include "SDL_timer.h"
#include "SDL_thread.h"
#include "SDL_systhread_c.h"
#ifdef DISABLE_THREADS
SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
{
SDL_SetError("SDL not configured with thread support");
return (SDL_sem *)0;
}
void SDL_DestroySemaphore(SDL_sem *sem)
{
return;
}
int SDL_SemTryWait(SDL_sem *sem)
{
SDL_SetError("SDL not configured with thread support");
return -1;
}
int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
{
SDL_SetError("SDL not configured with thread support");
return -1;
}
int SDL_SemWait(SDL_sem *sem)
{
SDL_SetError("SDL not configured with thread support");
return -1;
}
Uint32 SDL_SemValue(SDL_sem *sem)
{
return 0;
}
int SDL_SemPost(SDL_sem *sem)
{
SDL_SetError("SDL not configured with thread support");
return -1;
}
#else
#include <kos/sem.h>
struct SDL_semaphore
{
semaphore_t sem;
};
SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
{
return (SDL_sem *)sem_create(initial_value);
}
/* WARNING:
You cannot call this function when another thread is using the semaphore.
*/
void SDL_DestroySemaphore(SDL_sem *sem)
{
if ( ! sem ) {
SDL_SetError("Passed a NULL semaphore");
return;
}
sem_destroy(&sem->sem);
}
int SDL_SemTryWait(SDL_sem *sem)
{
int retval;
if ( ! sem ) {
SDL_SetError("Passed a NULL semaphore");
return -1;
}
retval = sem_trywait(&sem->sem);
if (retval==0) return 0;
else return SDL_MUTEX_TIMEDOUT;
return retval;
}
int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
{
int retval;
if ( ! sem ) {
SDL_SetError("Passed a NULL semaphore");
return -1;
}
/* A timeout of 0 is an easy case */
if ( timeout == 0 ) {
return SDL_SemTryWait(sem);
}
retval = sem_wait_timed(&sem->sem,timeout);
if (retval==-1) retval= SDL_MUTEX_TIMEDOUT;
return retval;
}
int SDL_SemWait(SDL_sem *sem)
{
if ( ! sem ) {
SDL_SetError("Passed a NULL semaphore");
return -1;
}
sem_wait(&sem->sem);
return 0;
}
Uint32 SDL_SemValue(SDL_sem *sem)
{
if ( ! sem ) {
SDL_SetError("Passed a NULL semaphore");
return -1;
}
return sem_count(&sem->sem);
}
int SDL_SemPost(SDL_sem *sem)
{
if ( ! sem ) {
SDL_SetError("Passed a NULL semaphore");
return -1;
}
sem_signal(&sem->sem);
return 0;
}
#endif /* DISABLE_THREADS */